Self-ad justing counter-brace foe



UNITED sTATEs PATENT OFFICE. i

JOHN GRAY, OF NASHVILLE, TENNESSEE.

SELF-ADJUSTNG- COUNTER-BRACE FOR TRUSS-BRIDGES.;

Specification of Letters Patent No. 26,583, dated-December 27', 1859.

To all whom it may concern:

Be it known that I, JOHN GRAY, of Nash` ville, in the county ofDavidson, in the State of Tennessee, have invented a new and IniprovedMode of Adjusting Counter-Braces in TrusseBridges; and I do herebydeclare that the following is a full and exact description thereof,reference being had to the accompanying drawings, and to the letters ofreference marked thereon.

The nature of niy invention consists in applying a cast iron socket atthe top of each counter brace in a truss bridge in such a manner as tolift it up, and also providing the bottoni of the brace with a cast ironheel and key, which latter slips forward and under when the counterbrace is drawn up.

To enable others skilled in the art tomake und use my invention `I willproceed to decounter scribe its construction and operation.

I construct my truss in the` ordinary Way with top and bottoni chords;upright or radiating posts and truss braces and counter braces. Toprevent the counter braces from becoming loose and to increase tightnesswhen the bridge is put into use I spike the iron socket, F ig. l, to theunder side of the top chord and to the posts, making it exactly fit theangle formed by the two latter, as shown by the letters af" e a. I thenlit and insert the end of the counter brace, and then through the holesa a in the sides of the socket, Fig. l, I drive two spikes into thebrace. These hold the counter brace up firmly in position. Then I setunder the end and on top ofthebottom chord, as shown at front` view,Fig.l2,`the cast iron heel against the posts.

In Fig. 2 back .'ewPBfCis the inclined surface upon which the` adjusting,key,is1140 placed and slides.` `When. the heel,` Fig. 2,11., is setunder the brace itleaves a` space they` size and 'shape of the key...:This key `and; the surface B C at Fig.` `2 are made smoothso y, thatwhen the counter brace is liftedupfthe 145 1 key slides under andlillsthe space `justi as f l much as it is increased by lifting thebrace."` To hold the counter brace in its proper poy i sition at thebottom I have side flanges c c" .p in Fig. 2 cast on theheelg These keepthe key, as well as brace, in its proper positionf: When one end orportion cfa bridge near" the end is depressed by a weight andthe similarportion of the `other end is corre-3F33 g spondingly elevated thecounter braces `are` drawn up and the key being relieved it slips underand fills up `theincreased spaceand holds the brace tight whenthe bridgecornes to repose again. kf What I claim as my invention, and desire tosecure by Letters Patent, isf-` y ,i y b ,l The applicationto counterbraces in truss IK C bridges of a socket at the top; aheel and key s atthe bottoinbywhich the counter braces in truss bridges `are madeselfftighteningand adjusting as herein described. b f 1 JOI-IN GRAYL" pI/Vitnesses: p ISAAC LITTEN,

SAML. SENY.` i

